This invention relates to improved corrosion-resistant waterborne paints. It further relates to the latex polymers and surfactant combinations which are useful in preparing such paints.
Previously, attempts to create waterborne corrosion-resistant latex paints have concentrated generally on the incorporation of specific corrosion-inhibiting ingredients into the binder system or the selection of particular binder components designed to maximize corrosion resistance. For example, U.S. Pat. Nos. 4,243,416 and 4,243,417 teach latex paints containing a water soluble complex of a polyvalent transition metal, a volatile complexing agent and a corrosion inhibiting anion. U.S. Pat. No. 3,586,519 teaches the use of a mixture of di-basic ammonium citrate and a neutralized acidic phosphate co-ester of an aliphatic alcohol and a non-ionic adduct of ethylene oxide and an organic compound containing reactive hydrogen atoms. U.S. Pat. No. 4,049,596 teaches the use of zinc borate and barium metaborate pigments to provide corrosion resistance. U.S. Pat. No. 4,108,811 teaches the use of a blend of resins along with a corrosion-inhibiting pigment or pigments. U.S. Pat. No. 4,173,665 teaches the use of polychloroprene polymer latexes and corrosion inhibitors to provide corrosion protection. U.S. Pat. No. 4,649,170 teaches elastic, breathable underbody coatings containing corrosion inhibiting agents. U.S. Pat. No. 4,999,250 teaches the use of a salt of a metal (magnesium, calcium, barium or zinc) of a hydroxycarboxylic acid which can be added to either a paint, oil or grease to improve corrosion resistance when use on metal surfaces. U.S. Pat. No. 5,028,489 teaches adding a sol or gel containing salt to a polymeric coating to improve the corrosion-inhibiting properties of the coating. U.S. Pat. No. 4,968,741 teaches latexes made with phosphate surfactants and vinyl aromatic monomers to achieve corrosion-inhibitive waterborne coatings. U.S. Pat. No. 5,082,895 teaches the use of high levels of styrene and large particle size to create higher solids waterborne coatings having corrosion resistance. U.S. Pat. No. 4,812,510 teaches the use of sodium 2-acrylamido-2-methylpropane sulfonate to make stable small particle size latexes.